1. Field of the Invention
The present invention relates to a telephony communication system, and more particularly to a computer network telephony system.
2. Description of Related Art
Conventional network telephone communication is developed on the basis of an IP (Internet Protocol) network. A conventional network telephone system employs a normal fixed-line type of telephone set as a terminal. A service gateway converts audio signals transmitted from the normal telephone into IP packets, which are then transmitted over the IP network. Since the IP packets need not monopolize a particular communication channel, the cost of a long-distance telephone call using the network telephone system is greatly reduced.
However, the service gateway is generally provided by a telecommunication service provider, which charges subscribers for the service gateway. As a result, the cost of a short-distance telephone call using the network telephone system may be higher than the cost of making the same call using a normal telephone line. That is, the low-cost advantages of the network telephone system are generally limited to long-distance calls, and exclude short-distance calls. In addition, the service gateway may have to deal with a vast number of active subscribers during peak periods. At such times, the service gateway is liable to switch to a busy status, in which it is not able to cope with more call requirements. Newly active subscribers are made to wait.
Consequently, what is needed is a network telephony system that can convert the audio signals into the IP packets without the need for a service gateway.